Pyrometer



March 7, 1933. Q B THwlNG PYROMETER Filed Nov.` 8, 1929 Illlll n u l lfatented Mar. 7, A1933 UNITED vSTATES PATENT OFFICE cHAnm E. r'HwING, lor PHILADELPHIA, PENNSYLVANIA, AssIGNoB, rro THWLNG.

INSTBUMENT'COMPANY, oF PHILADELPHIA, PENNSYLVANIA, A COBPOHATION or' PHNNsYLvANIA 'mourn Appmation mea November s. 192s. semi No. 405,736.

This invention relates pyrometers, and particularly refers to radlation pyrometers. One object of the inventlon 1s to provide a radiation pyrometer of the general type describedinmy prior application, 'Serlal No. 54,316, filed eptember 3, 1925, u on which Patent No. 1,734,837 was granted ovember 5, 1929, characterized by the relai is an improvement over the pyrometer described in the above-referred to patent and provides the substitution of a tubular mirror for'the converging lense.

Another object of my invention 1s to provide `a device of the class described of compact and rugged design suitable for inexpen-` be apparent when taken in connection with the accompanying drawing, in which Fig. 1 is a longitudinal sectional view of a yrometer embodying my invention;

ig. 2 is a partial longitudinal sectional view of a modification thereof;

' Fig. 3 is a transverse sectional view taken on the line III- III of Fig. 1, illustrating the tubular mirror;

Fi 4 and 5 are views taken on the lines IV T and V'V of Fig. 1, illustrating the detector; and

Fi .6 is a sectional view taken alongthe line -VI of Fig. 1, showing the opposite sidefof the detector support. 1.

In Fig. 1 is shown a pyrometer 1 which comprises an elongated tube having front and rear sections 3 and 4 which have adjacent ends 5 and 6 threaded for thereception of a coupling sleeve 7. A ring 8 ispro vided which is threaded on its periphery and is'positioned intermediate the adjacent l ends 5 and 6. A front end 11 of the section 3 is threaded for the reception of a cap l2 `a sleeve 16.

adapted to clamp a diaphragm 14Y which is provided with a central opening 15 against A pair of rings 17,17 may be positioned intermediate the sleeve andV diaphragm 14. A second diaphragm 18 55 having a central opening 19 is mountedon a ring 21 adapted to it within the other end ofthe front tube section 3. The diaphragm 18 is secured on the rin 21 by the screws 22 and 23. A plurality o additional 60 sleeves 24 are positioned intermediate the sleeve 16 a'nd the supporting rin 21and are spaced by rings 25 similar to t e 'r' 17. The sleeves 16 and 24 and the `rings 1 21 and 25, constituting the inner elements of the radiation tube section 3, are coated with a black material. The purpose of this is to permit radiant energy to pass without obstruction through the apertures 15" and 19 to a diaphragm 52 and into the tubular mirror 53. The diaphragm 52 comprises a plain thin disc of quartz glass. The ur- Apose of this quartz diaphragm is to ee out foreign material, such :as dust an fumes, to prevent the internal mirrored surface of the tube 53 from deteriorating and becoming dull from the action of any such foreign material'. The section 4 has positioned therein a detector 26 which is in the form of a thermo-electric device compris- 80 ing a plurality of thermocouples 27 connected in series-circuit relation and associated with external circuits by means of a pair of. conductors 28 and '29. The conductors are respectively connected to bindin posts' 31 and 32supported on a plate 33 camped to a rear end 34 of the tube section 4 by means ofa threaded cap 35.,-

Each thermocouple may comprise a pair of elements 36 and 37 which extend inwardly '90 `from supporting posts 38 and 39l to a common junction point 41. The junction points of the several thermocouples are closely spaced and positioned at the principal focus of a concave reflector 42 mounted `on a 95 threaded adjusting member 43 supported by a plate 44 which also serves to su portthe posts 38 and 39. Themember'44 clbsely fits within the tube section `and it may be spaced from the rear end 34 by means of a 100 l sleeve Itadiant'energy entering the tube tioned against one end of the tubular the thermocouples 27.

' may pass be reecting surface 46.

section 4 through the diaphragme 18 and 52 is transmitted through a tube 53, having its lished and mirrored,

inner surface hi hly to a conical or giurie -shaped relecti element 46 also having an inner highlypo is'hed The purpose of this conical or funnel-shaped element is to concentrate the radiant energy -upon mocouples 27 The tubular mirror 53' and the funnelhaped reflecting element. 46 are mounted l on 'brassrings 48 and 48 and the' conical element 46 hasfits larger end` simlrror and its smaller end is in proximt to the thermocouples 27. Ihe conical re ector 46 and the tu ular mirror 53 may-be made as an llamara!...ifA desired,., Y Y The supporting [ring 48' may .be positioned at the proper distance with respect to the thermocouples by means of a 49 and 51, the first of whic extends between the ring 48"- and the central ring 8. The -rings 48 are positioned in the' notches along -thelen h o the sleeve 49. The sec ond spacing s eeve 51 is positioned between the ring 48 and the central ring 8. The rings 48 vare positioned in the notches 't for as separate units, as

along the length of the sleeve 49. The sec-p ond spacin sleeve 51 is positioned between the ring 48 and the thermocouple supporting plate 44. The spacin sleeves 45 and 51 and the supporting mem er 44 are coated with a black substance, as is the case `with the inner `members of the front tube section 3. Thus the radiant energy entering the tube section-4 is transmitted byv the tubular mirror 53 to the conical reflector surface 46', where it is concentrated and transmitted to y It is important to note that vthe tubular mirror functions to transmit radiant ener without absorption. Thus radiated energy rom the heated body, whose temperature it is desired to measure, is conveyed substantially undiminished to the detector. Any radiant energy which ond the thermocouples is vreflected back t ereon by the concave reflector In Fig.v 2. is shown a modification in which the tubular ,mirror `53 extends from the quartz diaphragm '52 directly*v to the thermocouples 27. In this modification, no" c oncentrating reflector is providedand theradiant energy passes directly from the quartz diaphragm 52. to "the thermocouples.V providing a tubularmirror for transmitting the radiant .energy instead of usinga cion-,fV

as 1s done in the prior art, all

verging lense, of the losses'which are inherent in-:snch

lenses ,are'substantiallyeliminated. In this modification, the tubular mirrorl is .of much smaller diameter than that shown in Fig. `1

so that the energy passing through it be the ther- A'ular mirror `cause currents air ofsleeves' detector,

By it said detector,

positioned concentrated and confined toa smallerarea and substantially all of it will be impressed -I on the thermocouples 27.

l The operation of the device is as follows :-When the front-end 11 of the pyrometer is pointed at a heated energy -therefrom passes through the diaphragm1 opening 15 and 19 to the -quartz diaphragrnf52 and is'transmitted by-ithe tub- 53 to the conical concentrating reflector 46, where a complex reflection takes place with the result that a maximummoncentration occurs at the thermocouples Such energy as passes beyond the kthermo-` couples is reilected backwardly by the concave reflector 42 so that the thermocouples are subjectedto a maximum concentration of energy.. The resultin electro-motive forces developed by the t ermocouples 27 to flow when a galvanometer 0r other indicating instrument is operatively associated with the binding posts 31 and 32.

It :is lapparent that other modifications and changes may be made inthe construction without departing Vfrom the invention and I, therefore, desire that only such limtations shall be im'posed as are indicated in the appended claims.

I claim:

1. -A pyrometer `comprising a thermo' couple, a conical concentratin reflector on operative relation to said conical reflector for transmitting radiant energy to said thermocouple.

2. A pyrometer comprising a detector, means for concentrating the rays on said and means comprising a tubular mirror adjacent said first-mentioned means for transmitting the rays to said concentratmg means.

3. A pyrometer comprising a thermocouple, a concave reflector on one side thereof, a conical concentrating reiector on the other side thereof, and a tubular mirror in operative relation to said conical reflector.

l4. A pyrometer compromising a thermocouplefa concave mirror on one side, a concentrating reflector on the otherl side, and a tubular mirror adjacent said reflector for body, the radiant flecton 5. A pyrometer comprising a 4casing having an opening, a diaphragm for said opening, a detector, a tubular mirror positioned phragm for transmitting radiant I energy to -and a concentratin reflector and said detector.

radiantl energy, the. other section containing a detector a tubular-mirror positioned withmtermediate said tub ar mirror...-

ometer comprisingv a sectional v tubefprovlded Vwith a coupling member, one-,-"

section of Asaid-tube vhaving an opening. for

interr'nediate lsaid detector. and said diaf in said tube, and a reflector adjacent said tubular mirror for concentrating the rays passing through said tubular mirror.

A pyrometer comprising a tube having an opening, a diaphragm for said opening adapted to permit radiant energy to enter said tube, a detector positioned within said tube, a tubular mirror positioned intermediate said detector and said diaphragm, a second diaphragm in operative relation to said tubular mirror, and a retlector for concentrating the radiant energy passing through said'tubular mirror on said detector.

8. A pyrometer comprising a tube having an opening, a diaphragm for said opening adapted to permit radiant energy to enter said tube, a detector positioned within said tube, a tubular mirror positioned intermediate said detector and said diaphragm, a second diaphragm in operative relation to said tubular mirror, a reflector forconcentrating the radiant energy passing through said tubular mirror on said detector, and a second concentrating reector adjacent to said detector.

9. A radiation pyrometer comprising a conical reector, a tubular mirror adjacent said refiector, heat-responsive means operatively associated With the apex of said re- Hector, and means for preventin the passage o undesired radiation to said tubular mirror.

10. In a radiation pyrometer, a tubular casing, a funnel-shaped concentrating reflector therein, a detector adjacent the apex of said reflector, and a tubular mirror arranged in said casing between the re-lector and the opening of said casing at a distance from said opening relatively great with respect to its distance from the said refiector, whereby the passage of substantially al1 the undesirable radiationthrough the tubular mirror is prevented.

CHARLES B. THWING. 

